Learn More
Reexpansion of collapsed lung creates intrapulmonary shear forces. In an earlier study we showed that application of a negative end-expiratory airway pressure (NEEP) to normal rabbit lungs in vivo produced tidal collapse and reexpansion with transient changes in compliance and gas exchange but no histologic damage. In the present study we examined NEEP in a(More)
The reason why some infants with respiratory distress syndrome fail to respond to surfactant, or respond only transiently, is incompletely understood. We hypothesized that resuscitation with large breaths at birth might damage the lungs and blunt the effect of surfactant. Five pairs of lamb siblings were delivered by cesarean section at 127-128 d of(More)
The possible occurrence of lung damage if alveolar units are allowed to collapse and reopen breath by breath during mechanical ventilation with normal tidal volumes was investigated. Anaesthetised, paralysed, open chest rabbits were subjected to either intrathoracic negative (NEEP; n = 6) or positive (PEEP; n = 6) end-expiratory pressure during volume(More)
BACKGROUND Carbon dioxide elimination (VCO2) at steady state corresponds to the metabolic rate. A change in tidal ventilation will lead to a transient response in VCO2 if other determinants of VCO2 are constant. This principle may be applied in the critical care unit to reset ventilators. OBJECTIVE To define and characterize the transient response of VCO2(More)
The aim of this study was to determine whether the effects of alveolar distention and surfactant dysfunction on alveolocapillary barrier function are different and additive. Pulmonary clearance of aerosolized technetium-99m-labelled human serum albumin (99mTc-HSA) was used to characterize barrier function after perturbing the surfactant system with the(More)
Failure of neonatal patient triggered ventilation may reflect a delay in delivery of flow relative to the inspiratory effort of the infant. Transmission of diaphragmatic contraction to the sensor site (patient delay) and further transmission to and within the sensing device (device delay) both contribute to the delay in triggering. Patient and device delays(More)
We measured the pulmonary clearance of technetium-99m-labeled diethylenetriamine pentaacetatic acid (99mTc-DTPA) for 3 h after perturbation of the surfactant system by administration of the detergent dioctyl sodium sulfosuccinate in aerosol. Forty-two rabbits were anesthetized with pentobarbital sodium. Tracheostomies were performed, and the rabbits were(More)
BACKGROUND Breakdown of the alveolo-capillary barrier is a characteristic feature of respiratory distress syndrome. Restoration of alveolo-capillary barrier function may be an important aspect of surfactant replacement therapy. We examined the effect of surfactant instillation on alveolo-capillary barrier function in an experimental model of surfactant(More)
A model incorporating compliance, resistance, inertia, and the thermal time constant of plethysmographs is used to describe the effect of its dynamic properties on measured respiratory parameters. Using numerical simulation we studied the effect of distortion of flow signals from 13 infants in whom flow and esophageal pressure had been recorded. The(More)
Respiratory mechanics was studied in 11 rabbits at tidal volumes (VT) of 6.7, 10, and 20 ml/kg. Flow interruptions were performed during the full respiratory cycle. The viscoelastic pressure (Pve) was measured as the dynamic elastic pressure (Pel(dyn)) after flow cessation minus the static elastic pressure (Pel(st)). Static elastic and viscoelastic(More)